Original Preface. The Catholic Encyclopedia, as its name implies, proposes to give its readers full and authoritative information on the entire cycle of Catholic interests, action and doctrine. What the Church teaches and has taught; what she has done and is still doing for the highest welfare of mankind; her methods, past and present; her struggles, her triumphs, and the achievements of her members, not only for her own immediate benefit, but for the broadening and deepening of all true science, literature and art  all come within the scope of the Catholic Encyclopedia. It differs from the general encyclopedia in omitting facts and information which have no relation to the Church. On the other hand, it is not exclusively a church encyclopedia, nor is it limited to the ecclesiastical sciences and the doings of churchmen. It records all that Catholics have done, not only in behalf of charity and morals, but also for the intellectual and artistic development of mankind. It chronicles what Catholic artists, educators, poets, scientists and men of action have achieved in their several provinces. In this respect it differs from most other Catholic encyclopedias. The Editors are fully aware that there is no specifically Catholic science, that mathematics, physiology and other branches of human knowledge are neither Catholic, Jewish, nor Protestant; but when it is commonly asserted that Catholic principles are an obstacle to scientific research, it seems not only proper but needful to register what and how much Catholics have contributed to every department of knowledge.

No one who is interested in human history, past and present, can ignore the CatholicChurch, either as an institution which has been the central figure in the civilized world for nearly two thousand years, decisively affecting its destinies, religious, literary, scientific, social and political, or as an existing power whose influence and activity extend to every part of the globe. In the past century the Church has grown both extensively and intensively among English-speaking peoples. Their living interests demand that they should have the means of informing themselves about this vast institution, which, whether they are Catholics or not, affects their fortunes and their destiny. As for Catholics, their duty as members of the Church impels them to learn more and more fully its principles; while among Protestants the desire for a more intimate and accurate knowledge of things Catholic increases in proportion to the growth of the Church in numbers and in importance. The Catholic clergy are naturally expected to direct inquirers to sources of the needed information; yet they find only too often that the proper answers to the questions proposed are not to be met with in English literature. Even the writings of the best intentioned authors are at times disfigured by serious errors on Catholic subjects, which are for the most part due, not to ill-will, but to lack of knowledge. It would be fatuous to hope to call into immediate existence a Catholic English literature adequate to supply this knowledge and correct errors. The Encyclopedia, therefore, is the most convenient means of doing both, enabling, as it does, the foremost Catholic scholars in every part of the world to contribute articles in the condensed form that appeals to the man of action, and with the accuracy that satisfies the scholar.

Designed to present its readers with the full body of Catholic teaching, the Encyclopedia contains not only precise statements of what the Church has defined, but also an impartial record of different views of acknowledged authority on all disputed questions. In all things the object of the Encyclopedia is to give the whole truth without prejudice, national, political or factional. In the determination of the truth the most recent and acknowledged scientific methods are employed, and the results of the latest research in theology, philosophy, history, apologetics, archæology, and other sciences are given careful consideration.

The work is entirely new, and not merely a translation or a compilation from other encyclopedia sources. The Editors have insisted that the articles should contain the latest and most accurate information to be obtained from the standard works on each subject. Contributors have been chosen for their special knowledge and skill in presenting the subject, and they assume the responsibility for what they have written. Representing as they do Catholic scholarship in every part of the world, they give the work an international character.

The Encyclopedia bears the imprimatur of the Most Reverend Archbishop under whose jurisdiction it is published. In constituting the Editors the ecclesiastical censors, he has given them a singular proof of his confidence and of his desire to facilitate the publication of the work which he has promoted most effectively by his influence and kindly co-operation.

The Editors take occasion on the appearance of this first volume to express their gratitude to all who have taken part with them in this enterprise; in particular to the hierarchy for their cordial endorsement; to Catholic publishers and to the editors of the Catholic press for their frequent courtesies; to the contributors for their ready co-operation; to the original subscribers for their generous support; to the directors of the Company organized specially to produce the work, and to many non-Catholics for their kindly encouragement.